Lens housing support linkage for bellows type cameras

ABSTRACT

A linkage for supporting an extendable lens housing of a bellows type camera includes two identical link assemblies comprising link bars maintained in symmetrical relation to each other by meshed spur gear segments. The compactness afforded by the subject linkage construction allows the linkage to be concealed within the camera bellows without sacrificing the accuracy with which the lens housing is maintained in parallelism with the camera body member.

O United States Patent [151 3,668,992 Harvey June 13, 1972 [54] LENSHOUSING SUPPORT LINKAGE 582,995 5/1897 French"; ..95/39 FOR BELLOWS TYPECAMERAS 713,597 11/1902 Brownell ..95/39 [72] Inventor: Donald M.Harvey, Rochester, NY. I FOREIGN PATENTS OR APPLICATIONS [73] Assignee:Eastman Kodak Company, Rochester, 150,354 6/1903 Gen'nany ..95/39 N.Y.Primary Examiner-SamuelS. Matthews [22] Flled May 1970AssislantExaminer-Russell B. Adams, Jr. [211 App], 33,679Attorney-Robert W. Hampton and J. Addison Mathews [57] ABSTRACT [52]U.S.Cl.... ..95/39 [51] Int CL A linkage for supporting an extendablelens housing of a bel- [58] Field of Search ..95/39; 220/8 3"? WP?camera i 9 ldemlcal l assemblies 7 prising lmk bars maintained insymmetrical relation to each it other by meshed spur gear segments. Thecompactness af- [56] Re erences c ed forded by the subject linkageconstruction allows the linkage N E S ES P N to be concealed within thecamera bellows without sacrificing l 939 203 12/1933 Ch st 95/39 theaccuracy with which the lens housing is maintained in n 16 n H 'thth bodbe 2,143,385 1/1939 Flatt ..95/39 par 6 smwl ecamera ymem r 2,143,1251/1939 Headlee ..95/39 4Cla1ns,4Drawln g Figures u 7 l5 I? i v I2 33 i i3' a "a 29 I 28 II is I 2| 23 27 32 E l as 3? 3s I Ill h J l-.- l3 I In1 1 E! 1 iv 5' 1 :7 i i H, i 7 7 I?" r; I 7 57 j' I4 U l P [31' 3 's 241 3| 1i 27 I] I I \JTKJ 16 i ll 3 I PATENTEDJUH 13 I972 DONALD M. HARVEY23 INVENTOR.

lay/W WM M ATTORNEYS BACKGROUND OF THE INVENTION 1. Field oftheInvention The present invention relates to photographic cameras and moreparticularly to linkages for supporting an extendable lens housing of abellows type camera.

2. Description of the PriorArt Many types of linkages have been devisedin the past for supporting an extendable lens housing .of bellows typeternally of the bellows. However, since such a linkage is notparticularly attractive, it obviously would be preferable to conceal itwithin the bellows, thereby not only enhancing the appearance of thecamera but also eliminating the need to polish or plate the linkagecomponents.

SUMMARY OF THE INVENTION In accordance with the present invention alinkage for supporting an extendable lens housing of a bellows typecamera in parallel relation to the camera body member comprises twosubstantially identical link assemblies which are preferably locatedwithin the camera bellows at opposite sides of the center axis thereof.Each such assembly includes four similar overlapping link bars made offlat metal or some other rigid material. The two rearward link bars ofsuch assembly are pivotally connected to the camera body in crossedrelation to each other and are provided with meshing spur gear segmentswhich cause them to pivot in unison in opposite directions. The twocorresponding forward link bars are pivotally supported in the samemanner to the lens housing and are likewise provided with meshing spurgear segments. The end of each rearward link bar opposite the gearsegment thereof is pivotally connected to the corresponding end of theopposite forward link bar, thus coordinating the movement of all thebars comprising that link assembly and maintaining their respectivepivot points in rectilinear relation to each other. Abutment meansassociated'with the link bars allow both link assemblies to be extendedto the same predetermined maximum length to establish the extendedposition of the lens housing. The link bars comprising each linkassembly are located in staggered relation to each other so that allfour bars can overlap each other; thereby allowing the retracted linkageto be'very compact. This construction therefore allows such a linkage tobe concealed within the camera bellows without sacrificing the accuracyand rigidity with which the lens housing is maintained in parallelismwith the camera body.

Various means for practicing the invention and other advantages andnovel features thereof will be apparent from the following detaileddescription of an illustrative preferred embodiment of the invention,reference being made to the accompanying drawings in which likereference numerals denote like elements.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a fragmentary partially cross sectioned side elevational viewof a camera provided with an illustrative lens housing support linkagelocated within the camera bellows, which is shown fully extended andpartially broken away to depict details of the illustrative linkage;

FIG. 2 is a plan view of the camera structure shown in FIG. 1 in whichthe camera and bellows structures are similarly illustrated partiallybroken away and cross sectioned;

FIG. 3 is a fragmentary side elevational view corresponding to FIG. 1but depicting the bellows and the support linkage in retractedcondition; and

FIG. 4 is a fragmentary cross sectional end elevational view taken alongline 4-4 of FIG. 3.

DESCRIPTION OF THE ILLUSTRATIVE PREFERRED EMBODIMENT The illustrativecamera depicted somewhat schematically in the accompanying drawingscomprises a body member 11 provided with a rear wall member 12 whichsupports the exposure area of a strip of film 13 in a flat plane behinda rectangular exposure window 14 located within recess 15 of the bodymember. The lens support housing 16, which carries the camera lens andshutter, not shown, is movable between an extended position illustratedin FIGS. 1 and 2 and -a retracted position, depicted in FIGS. 3 and 4,in which it is received within body member recess 15.

The illustrative camera bellows 17 is of the type described in commonlyassigned copending U.S. Pat. Application Ser. No. 33,678, entitledMolded Plastic Bellows, filed in my name on May 5, 1970, comprisingaplurality of telescoping tubular sections 18 joined by appropriatelight sealing means which also prevent the bellows sections fromseparating. The largest and smallest telescoping bellows sections areattached respectively to the camera body and to the lens housing,thereby preventing light from reaching the film except through the lens.When the lens housing is retracted, the bellows sections are telescopedinto each other within body member recess 15, as shown in FIG. 3.Although this type of bellows has a number of advantageous features asexplained in detail in the above-identified patent application, itshould be understood that the lens housing support linkage with whichthe present invention is concerned is equally suitable for use inassociation with other more conventional types of bellows.

The subject support linkage comprises two identical link assemblies 21and 22 whichare located within the camera bellows at opposite sides ofthe lens axis in parallel opposed alignment with each other. Each linkassembly comprises three identical flat link bars 23, 24 and 25, asimilar fourth link bar 26 and four identical spur gear segments 27. Thetwo link bars 23 and 24 comprising the forward pair of bars in eachassembly are provided with pivot shafts 28 extending through the gearaxis holes of the corresponding gear segments and are pivotally carriedby support webs 29 of the lens housing. A washer 30 is provided betweenweb 29 and the gear segment connected to each of the corresponding linkbars 24 to maintainparallelism between link bars 24 and the other linkbars. Pins 31 prevent relative pivotal movement between bars 23 and 24and the corresponding gear segments, which therefore maintain those barsat all times in symmetrical crossed relation to each other. The two linkbars 25 and 26 comprising the rearward pair of bars of each assembly aresimilarly supported for pivotal movement to internal walls 32 of thecamera body member by pivot rivets 33 extending through spacer washers34. The two gear segments associated with link bars 25 and 26 arelikewise meshed with each other and are similarly pinned to those twobars so that the latter pivot in unison in opposite directions.

The end of each rearward link bar opposite the gear segment thereof ispivotally connected to the corresponding end of the opposite forwardlink bar of a hinge rivet 35, thus coordinating the movement of all ofthe bars of each link assembly and maintaining their respective pivotpoints in rectilinear relation to each other.

As best shown in FIG. 2, the two outermost link bars 26 are bent toprovide transverse portions 36 which allow those bars to be connectedwith the corresponding innermost forward link bars 23. Accordingly, allfour bars are located in different planes and can overlap each other topermit the linkage to be retracted as illustrated in FIG. 3. To affordmaximum compactness of the retracted linkage assembly, each bar isprovided with an edge notch 37 adapted to accommodate the respectivewasher adjacent the pivot means by which the opposite bar of the samepair is supported to the camera structure.

The fully extended position of the linkage is defined by the abutment ofthe bent portions 36 of link bars 26 with the adjacent edges of thecorresponding link bars 25 as shown in FIG. 1; thereby insuring that thelens assembly is located in parallel relation to the film'place at apredetermined fixed distance therefrom. Coil springs 38 encircling pivotshafis 28 apply resilient torque to those shafts to bias the lenshousing to its fully extended position, from which it can be movedmanually to itsretracted position where it is engaged by a releasablelatch device, not shown.

, Since both link assemblies have the same extended length, they neednot necessarily move precisely in unison with each other to insureparallelism between the extended lens housing and the film plane. It'isadvantageous, however, that the movement of both link assemblies becoordinated to prevent twistingof the linkage, which can readily beaccomplished by con: necting both such assemblies to a common pivotshaft carried by the lens housing. Alternatively, two of the illustratedopposed pivot shafts 28 can be connected to each other by means of a dogtype coupling 39, which provides the further advantage of affording alimited amount of rotational freedom between those two shafts to avoidpossible binding resulting from dimensional inaccuracies in the linkassemblies.

Because it utilizes a plurality of identical reversible components, thesubject lens housing support linkage is obviously very inexpensive toproduce, particularly since those components' need not be finished ifthey are concealed within the camera bellows. Furthermore, the meshedgear segment arrangement employed in the subject linkage provides veryaccurate parallelism and rigidity by providing a relatively small ratiobetween the transverse and longitudinal dimensions of the imaginaryrectangle defined by the four end pivot points of each link assembly. I

The invention has been described in detail with particular reference toan illustrative preferred embodiment thereof, but it will be understoodthat variations and modifications can be effected within thespirit andscope of the invention.

1 claim:

1. A photographic camera for exposing film, said camera comprising: abody member for receiving the film; a lens housing carrying a lens foreffecting exposure of the film; a collapsible-bellows extending betweensaid body member and said and retractable support linkage within saidlight-tight chamber for movably supporting said lens housing in parallelrelation to said body member, said support linkage comprising twosubstantially identical link assemblies located in opposed parallelrelation relative to each other, each of said link assemblies including:

a. two rearward link bars pivotally supported at their rearward ends tosaid body member by respective first pivot meansfor locating saidrearward ends in spaced relation relative to each other, v

. two meshing first gear segments one each attached to correspondingones of said rearward link bars in concentric relation to said firstpivot means, said meshing first gear segments maintaining said rearwardlink bars in crossed relation relative to each other, Y I 0. two forwardlink bars pivotally supported at their forward ends to said lens housingby respective second pivot means for locating said forward ends inspaced relation relative to each other, o ne each of said forward linkbars corresponding to one each of said rearward link bars, two meshingsecond gear segments one each attached to corresponding ones of saidforward link bars in concentric relation to said second pivot means,said meshing second gear segments maintaining said forward link bars incrossed relation relative to each'other, and

e. hinge means pivotally connecting the forward end of each of saidrearward link bars with the rearward end of its corresponding forwardlink bar; said substantially identical link assemblies being coupledtclfietherfor positive coordinated movement by a substantl ly rigidshaft extending between and immovably fixed to at least one of said twosecond meshing gear segments of each of said link assemblies.

2. The invention defined by claim 1 in which each of said linkassemblies comprises three substantially identical flat link bars andone bent link bar.

3. The invention defined by claim 2 in which each of said bent link barsdefines two parallel legs and a bent portion extending transversely ofsaid legs, said bent portion being engagable by'another one of said linkbars in crossed relation thereto to limit the maximum extension of saidbellows.

\ 4. The invention defined by claim 3 in which said link bars includeedge notch means for accommodating said pivot means when said bellows isin its fully retracted condition.

1. A photographic camera for exposing film, said camera comprising: abody member for receiving the film; a lens housing carrying a lens foreffecting exposure of the film; a collapsible bellows extending betweensaid body member and said lens housing for establishing a light-tightchamber between said body member and said lens housing; and anextendable and retractable support linkage within said light-tightchamber for movably supporting said lens housing in parallel relation tosaid body member, said support linkage comprising two substantiallyidentical link assemblies located in opposed parallel relation relativeto each other, each of said link assemblies including: a. two rearwardlink bars pivotally supported at their rearward ends to said body memberby respective firSt pivot means for locating said rearward ends inspaced relation relative to each other, b. two meshing first gearsegments one each attached to corresponding ones of said rearward linkbars in concentric relation to said first pivot means, said meshingfirst gear segments maintaining said rearward link bars in crossedrelation relative to each other, c. two forward link bars pivotallysupported at their forward ends to said lens housing by respectivesecond pivot means for locating said forward ends in spaced relationrelative to each other, one each of said forward link bars correspondingto one each of said rearward link bars, d. two meshing second gearsegments one each attached to corresponding ones of said forward linkbars in concentric relation to said second pivot means, said meshingsecond gear segments maintaining said forward link bars in crossedrelation relative to each other, and e. hinge means pivotally connectingthe forward end of each of said rearward link bars with the rearward endof its corresponding forward link bar; said substantially identical linkassemblies being coupled together for positive coordinated movement by asubstantially rigid shaft extending between and immovably fixed to atleast one of said two second meshing gear segments of each of said linkassemblies.
 2. The invention defined by claim 1 in which each of saidlink assemblies comprises three substantially identical flat link barsand one bent link bar.
 3. The invention defined by claim 2 in which eachof said bent link bars defines two parallel legs and a bent portionextending transversely of said legs, said bent portion being engagableby another one of said link bars in crossed relation thereto to limitthe maximum extension of said bellows.
 4. The invention defined by claim3 in which said link bars include edge notch means for accommodatingsaid pivot means when said bellows is in its fully retracted condition.